Survivors from a Pliocene Climatic Catastrophe: Gyrodactylus (Platyhelminthes, Monogenea) Parasites of the Relict Fishes in the Central Asian Internal Drainage Basin of Mongolia

We investigated the Gyrodactylus ectoparasites on relict fishes in isolated endorheic Central Asian Internal drainage basin Mongolia (The Hollow) and placed them into global phylogenetic framework based internal transcribed spacer regions of nuclear ribosomal DNA (ITS). Much rich Pliocene lacustrine ichthyofauna is extinct. sampled five riverine survivors: Altai osmans Oreoleuciscus humilis O. potanini (Leuciscidae), Mongolian grayling Thymallus brevirostris (Salmonidae), stone loaches Barbatula conilobus B. cobdonensis (Nemacheilidae). found eight species subgenus (Limnonephrotus) four G. (Gyrodactylus). Nine were identified as taxa described earlier, three new. The endemic carried species, only one wageneri group typical to salmonids (Gyrodactylus radimi sp. nov.), two nemachili (G. zavkhanensis nov., pseudonemachili Ergens Bychowsky, 1967), amurensis Akhmerov, 1952 was also osman loach. A parasite clade for Nemacheilidae overrepresented by tayshirensis nov. conilobus, mongolicus Dulmaa, 1970, 1936). Relaxed host specificity mentioned already Dulmaa evident. In updated ITS phylogenies freshwater-restricted subgenera, parasites from populations assumed positions concordant with a hypothesis multiple ancient introductions Euro-Siberian fauna, strong rarefaction cases divergence.